Boiler-furnace.



E. LANE.

BOILER FURNACE.

APPLICATION FILED SEPT.25. 1907.

Patented Dec. 28, 1915.

3 SHEETSSHEET I.

E. LANE.

BOILER FURNACE.

APFLICATION HLED SEPT-25. 1907. 1,165,981. Patented De0.28,1915.

3 SHEETS-SHEET 2.

W" 061%? jzwwzww E. LANE.

BOILER FURNACE.

APPLICATION FILED SEPT.25, I907.

1,165,91 Patented Dec. 28, 1915.

3 SHEETS-SHEET 3.

ii rre s ens EDWARD rare or er ee UITY, r se t;-

BOILER-FURNACE.

Specification of Iietters Patent.

reward a la n wi n reas pemb 907- Serial 2 39 .tii

To all whom it may concern Be it known that I, EDWARD LANE, a citizen ofthe United States, residing at Kansas City, in the county of Jackson andState of hilissouri, have invented certain new anduse ful Improvementsin Boiler-Furnaces, ,of which the following is a specif cation.

This invention relates to boilerfurnaces in general, but moreparticularly ,to those in which the fuel is supported grates niliich arestationary While the fuel. is burning, and in Whiclrthe constructionmust alto ,d .opportunity for stirring tlie fuel from time :to time witha poker or bar, the well lgnoiyn manner; and my invention has itsobjectto provide a furnace by which a ma steam poWer'can be developed with a pm mum consumption of fuel, by vwhich ,the heating properties of the fuelcan practically exhausted, nd .Which will operate economically and burnslack coalas, iciently as nut 0r lump coal, and, byii suringiii reperfect combustion, my invention conte nplates an improved furnace ofthis kind which Will operate With less tendency to produce smoke thanheretofore.

A further object is to produce a boiler furnace whereby the steampressure developed may be varied Without increasing or diminishing thequantity of fuel in the furnace.

A still further object is .to produce 'a fur nace in Whichthe heatradiated from clinlrers may be utilized in heating air entering .thefurnace to increase the effectiveness of ,the latter.

It is also an object to provide certain details and features ofconstruction and combinations tending to increase .the generalefliciency and service-ability of a furnace .in which the fuel, such assoft coal, is colred on a. series of relativelyvshort grates arranged instepped relation to each other, and in which the maximum combustionoccurs on the main or lowest grate, either alone or in combination meansfor supplying With heated air through the bridge Wall to the burningfuel on the main grate, the said heated air, ,When thus employed,serving to insure a more perfect combustion and tending to preventsmoke.

With these and other objects in iew as will hereinafter appear, theinvention consists in certain novel and peculiar features ofconstruction and organization, as hereinafter described and claimed; andorder that it may be fully understood reference is front series of riy 6f rm ng a ,fi l ie' e to be had to the accompanying drawings, in llbkh Ii i i i r ure 1, a section on dotted line I-l of Fig 2, of a boilerfurnace embodying my invention, the boiler shown full lines.

F gj 2, 1s a yiew' partly front elevation I and partlyin verticalsectiononltlie linen I Io f Fig. Fig. 3, is asectio n take 1011 theline 1114mmrig. 1. Fi i, is a y te- Ycal section intlre sage plap iiS 1, 015 amodified construction. Pig. 5, is an enlarged perspe'ctii e yieW tr onelof tlre air e a l boxes of the furnace Fig. 6,is a detail perspectiveView of a partition which may form a part o f my improvec m ce. Fig. 7is a section on the line VII-3 H 30f Fig. 3.

In the said drawings, .l indicates a steam boiler supportecl in and upontheibrickuiork :2 of the furnace "in the usual or' any preferred manner,Which bricliiy'orlr as shown is open" at its front end." dingfacrosscave recess 4; iii its upper edge wherein the I s of the recessprojecting upward some l fi-tle ,d stance above the heli- 5 indica tesbricks Which are arranged fiatboiler so as toleaye the portions of saidZontalplane of'the lo rer surface offthe Wise upon the horizontal arm ofsaid angle plate and are slip'ped thereon oi fertile rear edge for ,thepurpose of protecting the rii e ts mmediately above from the p upon (thefate hereinafter i'e ferredlto.

6 indicates brickwork superposed with respect to bricks 5 at opposite"sides of the last -named bricks which are immediately underthe center ofthe boiler, thebrickn ork M een bricksb andthe sides of"tlie mainbrickwork as shown in Fig. 2 it being noticedho i ever, that this 6' orbrickwork is built round the substantially triangle .Sllaped argements.7 of,noaz;les 8 and -enema portions of saidnoZ zles as will appear moreclearlyloy .1 y i reference to Fig. 1, v e 1t uullbenoticed top os e thenQZZ1es project rearwardly beyond the r e .s le i said-bri .,5 g t ,6, tbe ng also not ced that sa dnoz zles i l and brickwork slope downwardand rearward for a parflues 12 from each other and from the flues above,the last-named fines communicating with the usual chamber 13 at thefront end of the boiler, which opens upward as at 1 1 into the stack 15.The front end of the v boiler is closed by plate 16 and hinged door 17,the latter closing chambers 9 and a portion of chamber 13 by preference.

Vertically below angle bar 3 by preference, is a transverse cross bar 18preferably in the form of a T-bar pitched downward and rearward at aslight angle by preference and paralleling and rearward of said bar is asecond cross bar 19, which is preferably 1n the form of an angle barwith 1ts upper side pitched at the same angle as bar 18.

20 is a stationary grate pitched at the same angle as said bars andextending from one side wall of the furnace to the other and resting atits front edge on bar 19 and at its rear edge on transverse cross bar 21arranged a suitable distance forward of the bridge wall 22, whichpreferably has its upper end pitched as at 23 to deflect the heat andother products of combustion up toward and against the bottom of theboiler.

In Fig. 1 2 1 indicates arms secured to the bridge wall by preferenceand forming a pivot for the grate section 25 normally bridging the spacebetween arms 24: and cross bar 21, and depending from grate section 25is a lug 26 to which is pivoted the rear end of the grate operating rod27.

Said rod extends forwardly through the loop or ring 29 depending fromcross bar 18 and has its rear end bent upward as at 29 so as not tointerfere with the proper opening of grate 25. At its front end the rod27 is provided with a handle 30 and near said handle with a dependingportion 31 capable of passing through the loop 28 and engaging the lowerend of said loop as shown in Fig. 1, to hold the grate 25 in itsoperative position.

32 indicates a series of air tubes, one only beingshown, which extendthrough the rear wall and into the bridge wall and are adapted todischarge at their front ends into the downwardly and forwardly slopingpassages 33 in the bridge wall whereby air passing forwardly throughsaid pipes and heated during such passage shall be discharged downwardlyand forwardly onto the fire to cooperate with air admitted to thefurnace at other points in supplying sufficient oxygen to supportperfect combustion, it being further noticed that by reason of thedownward and forward inclination of passages 33 they cannot be cloggedup by coal. Cooperating with the air pipes 32 is a pair of air pipes 34of which only one appears, these air pipes being arranged by preferenceclose to the side walls of the brickwork and extending forwardly throughthe rear wall thereof and beyond the bridge wall and terminating attheir front ends in return-bend nozzles 35 for discharging the airconducted into the furnace by said pipes rearwardlyor toward the flameas it rises over the bridge wall.

- If the furnace is a wide one as is generally the case, the grate 25and the parts described in connection therewith including the operatingrod 27 will be in duplicate, it being noticed by reference to Fig. 2that said rod and the loops are so illustrated.

36 indicates one or more cleats projecting from the inner surface of theside walls of the brickwork as supports for certain slidable air boxes.In the event that the furnace is of such width as to make it undesirableto provide air boxes of corresponding width, I provide a verticalpartition 37 centrally between the walls and, equipped withcorresponding cleats 38, the partition resting upon the cross bars 18and 19 and hearing against the front edge of grate 20 by preference, itbeing obvious in this connection that if it be desired, more than one ofsaid partitions may be employed, an increase in the number of partitionslikewise necessitating an increase in the number of boxes so that saidpartitions may support certain of the boxes between them.

The boxes are arranged in superposed relation in any desired number, thesecond box or tier of boxes being shorter than the first,

the third shorter than the second and so on..

Each box is constructed as follows :-39 indicates the sides, lO the topof less length than the sides and 41 the bottom, the top and bottomconverging rearwardly and the bottom being of the same length as thesides, while the sides are provided with longitudinal external grooves42 for engagement with companion sets of cleats 36 and 38 as shown mostclearly in Fig. 2. Each box is provided with connected flanges 43depending from the margins of its bottom, which flanges are adapted toabout contact with the top 40 of the box next below so as to form inconjunction therewith a chamber tt, it being of course understood thatthe bottom box or tier of boxes will have flanges 43 resting upon thecross bars 18 and 19. The provision of an air chamber under the bottomof each box prevents such bottoms from being burned out in a short timewhile the flanges depending from said bottoms, particularly the side andrear flanges of all of the boxes except the lower one or tier, preventair from passing from such chambers into the furnace and in order tocontrol the volume of air entering the furnace through the boxes, the

latter are provided with lugs 45 carrying pivot rods 46 on which arepivoted lugs 47 of doors 48, said doors being adapted to maintain theirclosed positions against the ends of their r spective boxes by gravity,it

being noticed that the lugs 4:]? are capable of swinging under tl eforwardly projecting ends of the boxes when the doors are open so as tohold the latter in substantially the plane of the bottoms thereof inorder that the engineer or other attendant in charge of the furnace mayhave convenient access to the interior of the furnace through said boxeswhen necessary.

1:9 indicates a series of auxiliary grates, the undermost one beingarranged over the bottom box, at the rear end of and in substantiallythe same plane as the bottom of the box next above the said bottom box,the second auxiliary grate being arranged in the relation described withrespect to the second and third boxes, and the third grate shown beingarranged in the same relation to the topmost box as the second one is tothe intermediate box, it being further noted that said grates arearranged in step-like relation and are preferably provided with downwardly curved arms 50 at their rear sides, which arms tend to retardwithout reventing the feed of coal slack rearwardly on the underlyinggrates nor do they prevent the attendant from reciprocating a pokerthrough the boxes in the event that such action becomes necessary at anytime, it being further noticed that as these arms are subjected tointense heat during the operation of the furnace, they are preferablymade detachable so that in the event of burning off they can bereplaced. T he preferred method of effecting the attachment of the armsto the grates is to cast the rear bars of the latter with dovetailpockets 51 and the arms with dovetail heads 52 to slip down into saidpockets, though it is obvious that any other method of connecting thearms to the grates may be followed.

53 indicates a plate extending downwardly and rearwardly between theside walls of the brickwork and terminating at its rear end on thetopmost auxiliary grate and resting on a transverse plate 54 which fitsagainst the topmost box and extends from wall to wall or if in duplicatefrom the walls to the partition, to prevent the entrance of air abovesaid boxes and below plate 58, which plate in conjunction with the wallsof the furnace forms a fuel magazine. Said plate is additionallysupported by an angle bar 55 extending from side wall to side wall andto increase the capacity of the magazine, the plate may projectforwardly beyond said walls as at 56, the space between said projeetingportion and the front ends of the walls being closed by side pieces orwings 57.

In Fig. l, I show a modified construction whereby the heat of theclinkers after be ing removed from the main grate may be utilized toassist in heating the air conducted into the furnace by pipes 32. Toaccomplish this the bridge wall is provided with a chamber 38 in itsfront side, communicating with pipes 32 and extending across the forwardpart of said chamber is a cross bar 59 supporting brickwork 60 which inconjunction with cross bar 21, permanently supports a grate section ('31as a substitute for the hinge grate 25 of Fig. 1. 62 is av transversepivot carried by the bridge wall and 63 a plate pivoted thereon andadapted when horizontal to form a false bottom for chamber 58 andcapable of swinging downward so as to discharge clinker-s which may restthereon down upon the bottom of the furnace, at which point they areaccessible for removal by any suitable means. Pivoted at 6% is a swingframe 65 equipped with a roller 66 at its upper end engaging theunderside of hinged plate 63 and pivotally connected by a link 67 toswing frame 65, is a rod 68 having a handle 69 at its front end and adepending pert-ion 70 contiguous thereto and caoable of engag ing thefront side of or passing through a depending hook or loop 71 of crossbar 18, said hook or loop corresponding in form to the hook or loop 28.

in practice a fire is kindled upon the main grate in any suitable mannerand as the fire burns coal-preferably slack coal-isstored in themagazine so as to completely fill the same, it being obvious that someof this coal will fall from the topmost auxiliary grate down upon theone next below, and from the latter upon those below it, which coal willake fire from the burning fuel upon the 1 main grate and will cotiperatewith the lat ter in heating the boiler to produce steam, it beingobvious that the products of combustion pass rearwardly over the bridgewall which tends to dei'iect them u iiward against the boiler and aroundthe sides of the sameto the rear end of the boiler and then passesforwardly through the lines thereof, it being equally obvious that theheavier products of combustion, such as the dense smoke which arisesparticularly when firing the furnace because it is of greatest specificgravity, passes through the lower series of fines and into chambers 9from which chambers it passes into the enlargements of nozzles 8 and isdischarged rearwardly and downwardly by the latter into the combustionchamber. By this method the heavier products of combustion are retainedin the furnace for a sutlicient length of time for their heat producingproperties to become exhausted and as a result there is comparativelylittle combustible matter which escapes up through the stack to thelighter products which remain after the smoke has thus passed throughthe furnace under the boiler, pass forwardly through the upper series oflines of the boiler, all of the products which enter chamber 13 escapingto the atmosphere up through the stack.

\Vhen the furnace is operating at its minimum capacity it obtainssuflicient air to sup port combustion up through the lower grate andgrate 25 or 61, and in such event the fire will not burn fiercely on theauxiliary grates as the same are out of the direct line of draft, itbeing understood in this connection that such grates form feeders foreach other and for the main grate and that the fuel which eventuallyreaches the latter by dropping from one grate to another, reaches it inan incandescent state so that practically no smoke arises from the fuelburning thereon, it being further understood that the fire from saidgrate will be so fierce as to practically consume the comparativelysmall volume of smoke which arises from the fuel on the auxiliary gratesand particularly those most remote from the main grate. As a result ofthis action but little dense smoke obtains access to the boiler fiueswhen the furnace is operating with the air boxes closed.

When one or more of the air boxes is opened more smoke will of coursearise from the auxiliary grates, but even when all of the boxes areopened and the boiler is developing its maximum horse power in steam,the fuel which reaches the main grate from the auxiliary grates isincandescent so that most of the smoke arising from the fuel on theauxiliary grates will be consumed before it reaches the boiler flues.

When necessary the passage of the fuel from the auxiliary grates andmain grate can be facilitated by opening the doors 18 and running apoker through the boxes to push the fuel. rearward. The fine ashes findtheir way through the grates 20 and 25 or 61 and any clinkers which mayform in the construction shown in Fig. 1 are drawn through the openingbetween the bridge wall and cross bar 21, the rod 27 being manipulatedin an obvious manner to swing grate section 25 downward preliminary tothe removal of the clinkers and to return said section to its normalposition after the clinker has been removed, and it will be noticed inthis connection that by having passages 33 of the bridge wall slopingdownward and forward there will be but little danger of fuel from thegrate entering said passages in material volume.

In Fig. at the clinkers are adapted to be forced into chamber 58 andrest upon imperforate plate 63 from whence as long as they remain alive,the heat rises and assists in heating the air passing into the furnacethrough pipes 32. When the clinkers become inefficient for radiatingheat the attendant operates rod 68 and'forces the swing frame back topermit plate 63 to swing down and either drop the clinkers onto thebottom of the furnace or else render them accessible so that they can bedrawn or forced down. It will be seen that when rod 68 is pushedrearward to swing frame 65 in the same direction, link 67 will swingdown so that rod 68 actually imposes a direct force on the swing frame.When the frame and plate 63 is to be reelevated a pull on the rod swingsthe link upward and causes the same to partially raise plate 63. Theroller 66 then comes into engagement with the last named plate andcompletes its elevation. Should any of the boxes become defective byburning out or from any other cause they can be easily removed bysliding them forward without interfering with the remaining boxes. A newbox can be substituted for the old with the same ease and convenience.

From the above description it will be apparent that I have produced afurnace possessing the features of advantages enumerated as desirableand I wish it to be understood that I do not desire to be restricted tothe exact details of construction shown and described as obviousmodifications will suggest themselves to one skilled in the art.

lhe short grate in Fig. 1 is indicated by 25, and in Fig. t by 61. Thegrates 20 and 25 form a main grate structure, and the grates 20 and 61form a similar structure. In either case, means are provided, such as arod 27 and hinge connection, for dumping the clinkers and ashes. Ineither case, means are provided for introducing heated air through thebridge wall in opposition to the air that comes through the grates.Also, in each case, the boiler and the arch 5 serve to restrict thespace above the coking grates to cause a coking action.

Themain and coking grates are each, it will be seen, a complete grate initself, being formed in each case of integrally connected longitudinalgrate bars providing openings between them. Each grate is, however,properly regarded as a section of the entire grate structure. With theplates below the coking grates, one ofwhich plates extends outward incontinuation of the main grate, nothing can fall therefrom into the ashpit, and everything finally reaches the main grate, which is importantin the burning of slack or other fine coal.

With further reference to the coking of the coal or fresh fuel, it willbe observed that the smoke box of the boiler, comprising the chambers 9and 18, is disposed directly over the means for feeding the fuel to theuppermost coking grate, so that the heat of this smoke box assists incoking the coal. The entire grate sets well under the boiler,

with the construction shown and described, so that the fresh fuel from.the hopper must pass directly under the smoke box and the boiler support5 in order to reach the first or upper coking grate. coked before itreaches maximum combustion on the main grate, which latter sup ports themain body of burning fuel, and nothing can fall from the grate structureinto the ash pit until the fuel reaches the main grate.

Having thus described: the invention what I claim as new and desire tosecure byLetters Patent is 1. A furnace having a g ate, a fuel magazineoccupying a position forward of and above the grate, and a series of airboxes disposed in a stepped relation from the magazine to the grate andhaving openings to admit air to the fuel, said boxes having doors attheir front ends to control the passage of air to said openings andbeing slidably supported in the furnace.

2. A furnace provided with downwardly and rearwardly inclined cleats atthe inner sides of its side walls, cross bars below said cleats, apartition upon the cross bars provided. with similar cleats, air boxesat opposite sides of the partition removably sup ported on said crossbars and the lowermost cleats and having their tops terminating short ofthe rear ends of their bottoms, doors at the front ends of the boxes tocontrol the passage of air therethrough, superimposed tiers of boxeswhich gradually diminish in length toward the top arranged at oppositesides of the partition and provided with grooves removably engaging theupper cleats, a fuel magazine above the uppermost boxes and thepartition, and grates above the rear ends of the boxes.

3. A furnace having a main grate, a tubular air box arranged in thefurnace forward of and slightly above the said grate and having its topwall terminating forward of its bottom, the bottom of the box being insubstantially the same plane as the top of the grate, a door controllingthe passage of air through said box, and an auxiliary grate occupying astepped relation to the main grate and located over the rear end of thetubular air box.

41-. A furnace having a main grate, a magazine occupying a positionforward of and above the said grate, an auxiliary grate disposed abovethe main grate, arranged to receive fuel entering the furnace from themagazine, before such fuel reached the main grate. an air box arrangedbetween the said grates and having its top wall terminating adjacent theauxiliary grate and its bottom projecting under said grate, and a doorcontrolling the passage of air through the said box.

5, A furnace having a grate, a fuel maga- Thus the fuel is zineoccupying a position forward of and above said: grate, and series ofindepend ent superimposed air boxes between the bottom of the fuelmagazine and the front edge of the grate, each of said boxes. having adoor at its front end to. control the admission of air thereto.

6. A furnace having a main. grate, a fuel magazine forward of and abovesaid grate, a seriesof super-imposed air boxes disposed in a steppedrelation from the magazine to the grate and each provided at its frontend with a door to control the admission of air to the furnace from apoint above the grate and below the magazine and being slidaolysupported in the furnace, and a series of auxiliary grates correspondingin number to the superimposed boxes and each arranged above the innerend of an air box, the said grates being arranged to successivelyreceive the fuel and feed it downward and rearward from the magazine tothe main grate.

7. A furnace having a main grate, a series of superimposed tubular airboxes in front of said grate, a series of auxiliary grates occupying astepped relation tothe main grate and each located over the rear end ofan air box, and curved arms projecting downwardly and rearwardly fromthe auxiliary grates.

8. In a furnace, a bridge wall having a clinker cl unber open at itsfront side, a progressive feed grate from which hot clinker-s may passinto said chamber, an imperforate plate forming a false bottom for saidchamber, a swinging frame below the said plate to support the same in aclosed position, means for operating said frame to open or close theplate, and additional means for supplying air through said chamber andclinkers to the fuel on the grate.

9. In a furnace, a bridge wall having a clinker chamber open at itsfront side, a progressive feed grate from which hot clinkers may passinto said chamber, an imperforate plate forming a false bottom for saidchamber, a swinging frame below the plate to support the latter in aclosed position, a longitudinally movable rod, a link connecting therear end of the rod with the swinging frame, and additional means forsupplying air through said chamber and clinkcrs to the fuel on thegrate.

10. In a furnace, a stationary progressive feed grate, a bridge walltoward which the entire grate is inclined, means for supplying heatedair through said bridge wall to the fire on the grate, whereby the fuelcokes at the top of the grate and reaches the maximum combustion at thebridge wall air, and means at the lower end of the gate for dumping theclinker-s and ashes, which grate comprises a main grate section and aplurality of coking grate sections, the main grate section beingdisposed between the said dump and coking grate sections, with a clearspace under each section, the said sections being each composed of aplurality of parallel and longitudinally extending grate bars and aninclined plate extending under all of said coking grates to the frontedge of the main grate.

11. In a furnace, the combination of a stationary progressive feedgrate, a bridge wall toward which the grate is inclined, pipes forsupplying air through the bridge wall to the fire on the grate, achamber beyond the bridge wall for heating said pipes, means fordeflecting the hot air from said pipes downwardly upon the burning fuelon the main grate section, and means for dumping the clinkers where theair meets the maximum combustion at the lower end of the grate, saidgrate comprising main and coking grate sections, the main grate sectionbeing larger than any other section to support the main body of burningfuel.

12. In a furnace, a stationary progressive feed grate comprising a mainlower section and a' plurality of stepped upper sections, all inclinedor tilted forward, each upper section being a complete grate in itself,all the fuel being fed to the uppermost section, a shelf below eachupper section leading to the section below, each shelf being inclined ortilted like the grate, whereby the fuel is prevented from backing up onthe grate, a dump at the lower end of the main section, a bridge wall,and means for supplying heated air through the bridge wall to the fireon the grate.

13. In a furnace, a combustion chamber, a short grate, a main grate infront of the short grate, said main grate being larger than the shortgrate, a bridge wall against which the burning fuel carried on the mainand short grates is banked, a plurality of coking grates in front of themain grate, each coking grate comprising a plurality of parallel andlongitudinally extending grate bars, a plate disposed a distance beloweach coking grate, to provide a box below each coking grate, each cokinggrate being smaller than the main grate, means for delivering fuel tothe first coking grate, each grate adapted to feed the fuel to the nextgrate, means for restricting the combustion chamber above the cokinggrates, to cause the fuel to have a progressive coking action thereon,adapted to afford a free and maximum combustion on the main and shortgrates, and means for dumping the clinkers and ashes that form on theshort grate, the said boxes insuring an influx of heated air andaffording openings for a poker, the main and short grates supportingmore fuel than the other grates.

l4-. In a furnace, a combustion chamber,

a shortgrate, amain grate in .front of the,

short grate, said main grate being larger than the short grate, a bridgewall against which the burning fuel carried on the main and short gratesis banked, a plurality of coking grates in front of the main grate, aplate disposed a distance below each coking grate, to provide a boxbelow each coking grate, each coking grate being smaller than the maingrate, means for delivering fuel to the first coking grate, each grateadapted to feed the fuel to the next grate, means for re stricting thecombustion chamber above the coking grates, to cause the fuel to have aprogressive coking action thereon, adapted to afford a freeand maximumcombustion on the main and short grates, and means for dumping theclinkers and ashes that form on the short grate, the said boxes insuringan influx of heated air and affording openings for a poker, the main andshort grates supporting more fuel than the other grates, the said mainand coking grates, and the said plates, being all inclined or tiltedforward toward the bridge wall, the short grate being horizontal.

15. In a furnace, a combustion chamber, a short grate, a main grate infront of the short grate, said main grate being larger than the shortgrate, a bridge wall against which the burning fuel carried on the mainand short grates is banked, a plurality of coking grates in front of themain grate, a plate disposed a distance below each coking grate, toprovide a box below each coking grate, each coking grate being smallerthan the main grate, means for delivering fuel to the first cokinggrate, each grate adapted to feed the fuel to the next grate, means forrestricting the combustion chamber above the coking grates, to cause thefuel to have a progressive coking action thereon, adapted to afford afree and maximum combustion on the main and short grates, means fordumping the clinkers and ashes that form on the short grate, the saidboxes insuring an influx of heated air and affording openings for apoker, the main and short grates'supporting more fuel than the othergrates, and means for supplying heated air through the bridge wall inopposition to the influx of heated air through said boxes.

16. In a furnace, a combustion chamber, a short grate, a main grate infront of the short grate, said maingrate being larger than the shortgrate, a bridge wall against which the burning fuel carried on the mainand short grates is banked, a plurality of coking grates in front of themain grate, a plate disposed a distance below each coking grate, toprovide a box below each coking grate, each coking grate being smallerthan the main grate, means for delivering fuel to the first cokinggrate, each grate adapted to feed the fuel to the next grate, means forrestrictin'g the combustion chamber above the coking grates, to causethe fuel to have a progressive coking action thereon, adapted to afforda free and maximum combustion on the main and short grates, means fordumping the clinkers and ashes that form on the short grate, the saidboxes insuring an influx of heated air and affording openings for apoker, the main and short grates supporting more fuel than the othergrates, and means exposed to the products of combustion back of thebridge wall for supplying heatedair through the bridge wall to the fireon the said grates.

17. In a furnace, a combustion chamber, a main grate structure, a bridgewall against which the burning fuel carried on the main grate structureis banked, a plurality of coking grates in front of the main gratestructure, each coking grate comprising a plurality of parallel andlongitudinally extending grate bars, a plate disposed a distance beloweach coking grate, to provide a box below each coking grate, one of saidplates extending outward in continuation of the main grate, each cokinggrate being smaller than the main grate, means for delivering fuel tothe first coking grate, each grate adapted to feed the fuel to the nextgrate, means for restricting the combustion chamber above the cokinggrates, to cause the fuel to have a progressive coking action thereon,adapted to afiord a free and maxi mum combustion on the main gratestructure, and means for dumping the clinkers and ashes, the said boxesinsuring an influx of heated air and affording openings for the free useof a poker, the main grate structure supporting the main body of fuel inthe furnace.

18. In a furnace, a combustion chamber, a main grate structure, a bridgewall against which the burning fuel carried on the main grate structureis banked, a plurality of coking grates in front of the main gratestructure, a plate disposed a distance below each coking grate, toprovide a box below each coking grate, each coking grate being smallerthan the main grate structure, means for delivering fuel to the firstcoking grate, each grate adapted to feed the fuel to the next grate,means for restricting the combustion chamber above the coking grates, tocause the fuel to have a progressive coking action thereon, adapted toafford a free and maximum combustion on the main grate structure, meansfor dumping the clinkers and ashes, the said boxes insuring an influx ofheated air and affording openings for the free use of a poker, the maingrate structure supporting the larger body of fuel, and means exposed tothe products of combustion back of the bridge wall for supplying heatedair through the bridge wall to the fire on the said grates.

19. In a furnace, a combustion chamber, a

main grate structure, a bridge wall against which the burning fuelcarried on the main grate structure is banked, a plurality of cokinggrates in front of the main grate structure, a plate disposed a distancebelow each coking grate, to provide a box below each coking grate, eachcoking grate being smaller than the main grate structure, means fordelivering fuel to the first coking grate, each grate adapted to feedthe fuel to the next grate, means for restricting the combustion chamberabove the coking grates, to cause the fuel to have a progressive cokingaction thereon, adapted to afford a free and maximum combustion on themain grate structure, and means for dumping the clinkers and ashes, thesaid boxes insuring an influx of heated air and affording openings forthe free use of a poker, the main grate structure supporting the largerbody of fuel, the said main and coking grates and the said plates beingall inclined or tilted forward toward the bridge wall.

20. In a furnace, a combustion chamber, a main grate structure, a bridgewall against which the burning fuel carried on the main grate structureis banked, aplurality of coking grates in front of the main gratestructure, a plate disposed a distance below each coking grate, toprovide a box below each coking grate, each coking grate being smallerthan the main grate structure, means for delivering fuel to the firstcoking grate, each grate adapted to feed the fuel to the next grate,means for restricting the combustion chamber above the coking grates, tocause the fuel to have a progressive coking action thereon, adapted toafford a free and maximum combustion on the main grate structure, meansfor dumping clinkers and ashes, the said boxes insuring an influx ofheated air and affording openings for the free use of a poker, the maingrate structure supporting the main body of fuel in the furnace, andmeans for supplying heated air through the bridge wall in opposition tothe influx of heated air through said boxes.

21. In a progressive feed furnace, a main grate, a plurality of cokinggrates arranged in stepped relation to each other, with horizontal spacebetween, to coke and feed the fuel to said main grate, means for feedingall the fuel to the first coking grate, and means whereby the droppingsfrom each and every coking grate are caught and fed to the grate below,said main grate being larger than any other grate to support the mainbody of burning fuel.

22. In a progressive feed furnace, a main grate, a plurality of cokinggrates arranged in stepped relation to coke and feed the fuel to saidmain grate, with openings between the coking grates, and means forfeeding all the fuel to the first coking grate, wherey all he fuel stats at the p and. pro- 1 rm. 1.4m:

gresses slowly to the bottom, each coking grate being straight andinclined forward for its full length, to permit backing up of the fueland each coking grate having openings therein, said main grate beinglarger than any other grate to support the main body of burning fuel.

23. In a progressive feed furnace, a main grate, a plurality of cokinggrates arranged in stepped relation to coke and feed the fuel to saidmain grate, means for feeding all the fuel to the first coking grate,and an inclined plate below each grate, one of said plates extendingoutwardly in continuation of the main grate, whereby all droppings fromeach and every coking grate finally reach the main grate.

2a. in a progressive feed machine, a main grate, a plurality of cokinggrates arranged in stepped relation to coke and feed the fuel to saidmain grate, with openings between the coking grates, means for feedingall the fuel to the first coking grate, each coking grate being straightand inclined forward for its full length, and each coking grate havingopenings therein, and an inclined plate below each grate, one of saidplates eX- tending outwardly in continuation of the main grate, wherebyall droppings from each and every coking grate finally reach the maingrate. r V

25. In a progressive feed furnace, a main lower grate, a plurality ofupper coking grates arranged in stepped relation to coke and feed thefuel to said main grate, means for feeding all the fuel to the firstcoking grate, means for catching and feeding forward to the main grateanything falling through each and every one of said coking grates, and adump beyond the main grate, said main grate being larger than any othergrate to support the main body of burning fuel.

26. A progressive feed grate furnace comprising main and coking gratesarranged in stepped relation to each other, the main grate being longerthan any other grate to support the main body of burning fuel, and meansfor feeding the fresh fuel to the upper coking grate only, an inclinedplate leading to the front edge of each grate, and a dump at the rearedge of the main gate.

In testimony whereof I affix my signature, in the presence of twowitnesses.

ED /VARD LANE. lVitnesses:

H. C. Rononns, G. Y. THORPE.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

